"Sysadm::Install" executes shell-like commands performing typical
installation tasks: Copying files, extracting tarballs, calling "make".
It has a "fail once and die" policy, meticulously checking the result of
every operation and calling "die()" immediately if anything fails,
with optional logging of everything.
"Sysadm::Install" also supports a *dry_run* mode, in which it logs
everything, but suppresses any write actions.